//设置1像素
@mixin border-1px($color) {
  position: relative;
  &::after {
    display: block;
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    border-top: 1px solid $color;
    content: '';
  }
}

//取消1像素
@mixin border-none() {
  &::after{
    display: none;
  }
}

//设置背景图
@mixin bg-img($url) {
  background-image: url( $url + "@2x.png");
  @media (-webkit-min-device-pixel-ratio: 3), (min-device-pixel-ratio: 3) {
    background-image: url($url + "@3x.png");
  }
}
